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use std::fmt::{self, Debug};
use std::pin::Pin;
use std::sync::Arc;
use async_stream::stream;
use async_trait::async_trait;
use futures::future;
use futures::stream::{Stream, StreamExt, TryStreamExt};
use http::uri::PathAndQuery;
use once_cell::sync::Lazy;
use semver::Version;
use tokio::net::UnixStream;
use tokio::select;
use tokio::sync::mpsc::{self, UnboundedSender};
use tokio::sync::{oneshot, Mutex};
use tokio_stream::wrappers::UnboundedReceiverStream;
use tonic::body::BoxBody;
use tonic::codegen::InterceptedService;
use tonic::metadata::{AsciiMetadataKey, AsciiMetadataValue};
use tonic::service::Interceptor;
use tonic::transport::{Body, Channel, Endpoint, NamedService, Server};
use tonic::{IntoStreamingRequest, Request, Response, Status, Streaming};
use tower::Service;
use tracing::{debug, error, info};
use mz_ore::netio::{Listener, SocketAddr, SocketAddrType};
use mz_proto::{ProtoType, RustType};
use crate::client::{GenericClient, Partitionable, Partitioned};
use crate::codec::{StatCodec, StatsCollector};
pub type ResponseStream<PR> = Pin<Box<dyn Stream<Item = Result<PR, Status>> + Send>>;
pub type ClientTransport = InterceptedService<Channel, VersionAttachInterceptor>;
pub trait ProtoServiceTypes: Debug + Clone + Send {
type PC: prost::Message + Clone + 'static;
type PR: prost::Message + Clone + Default + 'static;
type STATS: StatsCollector<Self::PC, Self::PR> + 'static;
const URL: &'static str;
}
#[derive(Debug)]
pub struct GrpcClient<G>
where
G: ProtoServiceTypes,
{
tx: UnboundedSender<G::PC>,
rx: Streaming<G::PR>,
}
impl<G> GrpcClient<G>
where
G: ProtoServiceTypes,
{
pub async fn connect(
addr: String,
version: Version,
metrics: G::STATS,
) -> Result<Self, anyhow::Error> {
debug!("GrpcClient {}: Attempt to connect", addr);
let channel = match SocketAddrType::guess(&addr) {
SocketAddrType::Inet => Endpoint::new(format!("http://{}", addr))?.connect().await?,
SocketAddrType::Unix => {
let addr = addr.clone();
Endpoint::from_static("http://localhost") .connect_with_connector(tower::service_fn(move |_| {
UnixStream::connect(addr.clone())
}))
.await?
}
};
let service = InterceptedService::new(channel, VersionAttachInterceptor::new(version));
let mut client = BidiProtoClient::new(service, G::URL, metrics);
let (tx, rx) = mpsc::unbounded_channel();
let rx = client
.establish_bidi_stream(UnboundedReceiverStream::new(rx))
.await?
.into_inner();
info!("GrpcClient {}: connected", &addr);
Ok(GrpcClient { tx, rx })
}
pub async fn connect_partitioned<C, R>(
dests: Vec<(String, G::STATS)>,
version: Version,
) -> Result<Partitioned<Self, C, R>, anyhow::Error>
where
(C, R): Partitionable<C, R>,
{
let clients = future::try_join_all(
dests
.into_iter()
.map(|(addr, metrics)| Self::connect(addr, version.clone(), metrics)),
)
.await?;
Ok(Partitioned::new(clients))
}
}
#[async_trait]
impl<G, C, R> GenericClient<C, R> for GrpcClient<G>
where
C: RustType<G::PC> + Send + Sync + 'static,
R: RustType<G::PR> + Send + Sync + 'static,
G: ProtoServiceTypes,
{
async fn send(&mut self, cmd: C) -> Result<(), anyhow::Error> {
self.tx.send(cmd.into_proto())?;
Ok(())
}
async fn recv(&mut self) -> Result<Option<R>, anyhow::Error> {
match self.rx.try_next().await? {
None => Ok(None),
Some(response) => Ok(Some(response.into_rust()?)),
}
}
}
pub struct BidiProtoClient<PC, PR, S>
where
PC: prost::Message + 'static,
PR: Default + prost::Message + 'static,
S: StatsCollector<PC, PR>,
{
inner: tonic::client::Grpc<ClientTransport>,
path: &'static str,
codec: StatCodec<PC, PR, S>,
}
impl<PC, PR, S> BidiProtoClient<PC, PR, S>
where
PC: Clone + prost::Message + 'static,
PR: Clone + Default + prost::Message + 'static,
S: StatsCollector<PC, PR> + 'static,
{
fn new(inner: ClientTransport, path: &'static str, stats_collector: S) -> Self
where
Self: Sized,
{
let inner = tonic::client::Grpc::new(inner);
let codec = StatCodec::new(stats_collector);
BidiProtoClient { inner, path, codec }
}
async fn establish_bidi_stream(
&mut self,
rx: UnboundedReceiverStream<PC>,
) -> Result<Response<Streaming<PR>>, Status> {
self.inner.ready().await.map_err(|e| {
tonic::Status::new(
tonic::Code::Unknown,
format!("Service was not ready: {}", e),
)
})?;
let path = PathAndQuery::from_static(self.path);
self.inner
.streaming(rx.into_streaming_request(), path, self.codec.clone())
.await
}
}
pub struct GrpcServer<F> {
state: Arc<GrpcServerState<F>>,
}
struct GrpcServerState<F> {
cancel_tx: Mutex<oneshot::Sender<()>>,
client_builder: F,
}
impl<F, G> GrpcServer<F>
where
F: Fn() -> G + Send + Sync + 'static,
{
pub async fn serve<S, Fs>(
listen_addr: SocketAddr,
version: Version,
client_builder: F,
service_builder: Fs,
) -> Result<(), anyhow::Error>
where
S: Service<
http::Request<Body>,
Response = http::Response<BoxBody>,
Error = std::convert::Infallible,
> + NamedService
+ Clone
+ Send
+ 'static,
S::Future: Send + 'static,
Fs: FnOnce(Self) -> S + Send + 'static,
{
let (cancel_tx, _cancel_rx) = oneshot::channel();
let state = GrpcServerState {
cancel_tx: Mutex::new(cancel_tx),
client_builder,
};
let server = Self {
state: Arc::new(state),
};
let service = InterceptedService::new(
service_builder(server),
VersionCheckExactInterceptor::new(version),
);
info!("Starting to listen on {}", listen_addr);
let listener = Listener::bind(listen_addr).await?;
Server::builder()
.add_service(service)
.serve_with_incoming(listener)
.await?;
Ok(())
}
pub async fn forward_bidi_stream<C, R, PC, PR>(
&self,
request: Request<Streaming<PC>>,
) -> Result<Response<ResponseStream<PR>>, Status>
where
G: GenericClient<C, R> + 'static,
C: RustType<PC> + Send + Sync + 'static + fmt::Debug,
R: RustType<PR> + Send + Sync + 'static + fmt::Debug,
PC: fmt::Debug + Send + Sync + 'static,
PR: fmt::Debug + Send + Sync + 'static,
{
info!("GrpcServer: remote client connected");
let (cancel_tx, mut cancel_rx) = oneshot::channel();
*self.state.cancel_tx.lock().await = cancel_tx;
let mut request = request.into_inner();
let state = Arc::clone(&self.state);
let response = stream! {
let mut client = (state.client_builder)();
loop {
select! {
command = request.next() => {
let command = match command {
None => break,
Some(Ok(command)) => command,
Some(Err(e)) => {
error!("error handling client: {e}");
break;
}
};
let command = match command.into_rust() {
Ok(command) => command,
Err(e) => {
error!("error converting command from protobuf: {}", e);
break;
}
};
if let Err(e) = client.send(command).await {
yield Err(Status::unknown(e.to_string()));
}
}
response = client.recv() => {
match response {
Ok(Some(response)) => yield Ok(response.into_proto()),
Ok(None) => break,
Err(e) => yield Err(Status::unknown(e.to_string())),
}
}
_ = &mut cancel_rx => break,
}
}
info!("GrpcServer: remote client disconnected");
};
Ok(Response::new(Box::pin(response)))
}
}
static VERSION_METADATA_KEY: Lazy<AsciiMetadataKey> =
Lazy::new(|| AsciiMetadataKey::from_static("x-mz-version"));
#[derive(Debug, Clone)]
pub struct VersionAttachInterceptor {
version: AsciiMetadataValue,
}
impl VersionAttachInterceptor {
fn new(version: Version) -> VersionAttachInterceptor {
VersionAttachInterceptor {
version: version
.to_string()
.try_into()
.expect("semver versions are valid metadata values"),
}
}
}
impl Interceptor for VersionAttachInterceptor {
fn call(&mut self, mut request: Request<()>) -> Result<Request<()>, Status> {
request
.metadata_mut()
.insert(VERSION_METADATA_KEY.clone(), self.version.clone());
Ok(request)
}
}
#[derive(Debug, Clone)]
struct VersionCheckExactInterceptor {
version: AsciiMetadataValue,
}
impl VersionCheckExactInterceptor {
fn new(version: Version) -> VersionCheckExactInterceptor {
VersionCheckExactInterceptor {
version: version
.to_string()
.try_into()
.expect("semver versions are valid metadata values"),
}
}
}
impl Interceptor for VersionCheckExactInterceptor {
fn call(&mut self, request: Request<()>) -> Result<Request<()>, Status> {
match request.metadata().get(&*VERSION_METADATA_KEY) {
None => Err(Status::permission_denied(
"request missing version metadata",
)),
Some(version) if version == self.version => Ok(request),
Some(version) => Err(Status::permission_denied(format!(
"request version {:?} but {:?} required",
version, self.version
))),
}
}
}